Decoder



O 1962 c. E. ADLER ETAL 3,057,547

DECODER Filed May 8, 1957 4 Sheets-Sheet 1 Z= t q I /v0 PREMATURE ZONEOPERATION $614 LE SELECTOR COMPUTER POSTAGE SELECTOR co/v M01.

Pas mas ME rm INVENTOR5 CLARENCE E. ADLER BY DONWAN L. HALL w i m 1962c. E. ADLER ETAL 3,

DECODER Filed May 8, 1957 4 Sheets-Sheet 2 INVENTORS CLARENCE E. ADLERDONIVAN L. HALL ATTORNEYS Oct. 9, 1962 c. ADLER ET AL DECODER 4Sheets-Sheet 3 Filed May 8, 1957 INVENTORS CLARENCE E. ADLER DONIVANHALL ATTORNEYS WW M Oct. 9, 1962 c. E. ADLER ETAL 3,057,547

DECODER Filed May 8, 1957 4 Sheets-Sheet 4 O JIQ- INVENTORS CLARENCE E.ADLER DONIVAN L. HALL ATTORNEYS United States Patent 3,057,547 DECODERClarence E. Adler and Donivan L. Hall, Toledo, Ohio,

assignors, by mesne assignments, to Toledo Scale Corporation, Toledo,Ohio, a corporation of Ohio Filed May 8, 1957, Ser. No. 657,817 4Claims. (Cl. 235-1) This invention relates to electro-mechanicaltranslators and more particularly to mechanism for encoding and decodinginformation.

One object of the invention is to facilitate the accurate encoding ordecoding of information.

Another object is to reduce the power requirements of an encoding ordecoding mechanism.

Another object is to control the speed of the operation in a decodingdevice whereby certain functions are performed rapidly and others wherespeed may be detrimental to accuracy can be performed at speedsconsistent with the necessary degree of accuracy.

In accordance with the above objects, one form of this inventioninvolves a mechanical permutation selector including a plurality ofshiftable elements each bearing a group of notches and stationaryelements in alignment With the shiftable elements and also bearing aplurality of notches. The shiftable elements are provided with meanstending to urge them to a first position and second means operatingagainst the first means to urge them to a second position in response toan input signal. A searching means, in the form of an indexing pawl, iscaused to traverse the shifta-ble elements during an operating cycle andto be stopped by the engagement of the pawl in a series of aligned slotsin the stationary and shiftable elements. The engagement of a pawl inthe notch in the stationary element ensures that the shiftable elementswill be maintained in their respective positions and enables certain ofthe opposing forces driving the shiftable elements and the indexing pawlto be deenergized. This locking action of the pawl thus reduces theenergy necessary in operating the mechanism accurately, positivelypositions the indexing member, and conditions the mechanism so thatcertain functions of the current operating cycle can be reset for thenext succeeding operating cycle without losing the information fed tothe mechanism.

In order to further enhance the accuracy of operation while maintaininga high rate of operation and generating substantial mechanical forces,the initial conditioning of the indexing pawl for its searching cycle isaccomplished by a positive drive operating at relatively high speeds.This initial conditioning involves positioning the indexing pawl at oneend of its range of travel and lifting it free of the shiftable memberswhereby any frictional load by the pawl is eliminated while thosemembers are actuated by their driving means. The pawl and its drivingmeans are carried toward the opposite end of its range of travel by thetermination of the driving forces and the operation of a return spring.Engagement of the pawl, when in registration with an aligned group ofnotches in the stationary and movable elements, is ensured by retardingthe speed of movement of the pawl across the permutation elements duringits searching operation. One such means of accomplishing thisretardation is to employ a dashpot connected to the pawl driving means.

Another technique is to utilize a combination of a cam which becomeseffective as the driving means initiates its return to its initialposition with an electric motor arranged to provide dynamic braking.

A feature of this invention resides in positively fixing the position ofan index in an encoding or decoding device. Incidental to this feature,this means also relieves 3,057,547 Patented Oct. 9, 1962 ice certain ofthe opposing forces to which the system is subject, latching permutationmembers therein in fixed relationship and position.

Another feature resides in a driving mechanism of an encoder or decoderhaving sufiicient force to operate elements opposing substantial loadswherein the driving forces may be relieved from the system by a positivelocking mechanism during intervals of operation.

Another feature involves combining retarding means with a high speeddrive for the indexing mechanism whereby, during the indexing portion ofan operating cycle, suflicient time is given to the indexing function toassure its accurate and positive realization.

The above and additional objects and features of this invention will bemore fully appreciated from reading the following detailed descriptionwith reference to the accompanying drawings wherein:

FIG. I depicts the over-all combination, represented in functional blockdiagram form, of one utilization of the present invention in a computingweighing scale;

FIG. II is a diagrammatic perspective, with portions broken away, tomore fully illustrate more details of a signal stage of a mechanicaltranslator or decoder according to this invention;

FIG. III is a side view of a three-stage mechanical translator typicalof this invention;

FIG. IV is an end view of the mechanism of FIG. III; and

FIG. V is an enlarged detailed side view showing portions of theelements which positively retain the indexing member of the decoder.

A general representation of a typical system utilizing mechanismaccording to this invention as a mechanical decoder of electricalsignals is shown in FIG. I. The disclosed system is intended toautomatically prepare metered postage stamps or labels for packages thatare to be sent by parcel post and accordingly, comprises a computingscale coupled by means of the mechanism of this invention to a postagemeter.

In FIG. I a scale It conveniently of the countertop type, is providedwith means 11 to prevent its premature operation when a package, whichis to be provided with metered postage, is first placed on its loadreceiver. A computer 13 is rendered effective in the manner set forth indetail in the application of R. E. Bell and R. B. Williams, Jr. entitledLoad Measuring Apparatus, Serial No. 657,947, filed herewith, thedisclosures of which are incorporated herein by reference to illustratea system utilizing this invention. When the system is properlyconditioned, as indicated by the enabling means 11 at the instant motionin the movable system of the scale falls below a predetermined levelconsistent with accurate weight determination and by the operation of aselector 12 presetting constants and correlated multiplying factors forthe postal zone to which the package is addressed, computation iseffected by computer 13. As disclosed in further detail in thatapplication, zone selection is achieved by the operation of one of fivesets of self-hold contact closures in the zone selector 12. Completingone set of contact closures sets up an appropriate three order,multiplying factor through three contact closures, sets up a two digitpreset quantity of constant in the counters of the computer by means oftwo additional closures, and conditions a control integrated with themotion detecting means to activate the computer on the next completereadout cycle of the scale.

At the end of a readout cycle from the scale, controls are operated tolockout succeeding readout cycles from the computer and utilization ofthe information in the computer counters is initiated b operation of thedecoder of this invention. The information utilized by this mechanism isthe sum of the constant or minimum postal rate and the product of thepreset multiplying factor and the applied load on the scale. It isstored at the end of the first complete readout cycle in the decadecounters in binary code. Three decade counters supply the dollars andcents information to three sets of drivers in the output stage of thecomputer 13. Each driver energizes four solenoids in the decoder orpostage selector control 14 according to the coded information receivedfrom its decade. The drivers comprise amplifiers individual to eachoutput terminal of the decade counter, for example triodes which areeither cutoif or heavily conducting depending upon the signal from thedecade output terminals. Each amplifier is individual to a solenoid of adriver. The decoded signal is translated to mechanical displacement ofcontrol elements in a post-age meter 14' by means of decoder 14 andsuitable couplers. Upon completion of the decoding the postage meter isactuated by means of the decoder to print a metered label.

As shown in FIG. II, each of the four solenoids 15, .16, 17, and 18connected to a given driver (not shown) is associated with a mechanicaldecoder which converts the binary coded information, as indicated by therelative positions of the armatures 19, 20', 21, and 22 of the foursolenoids, to a position related to a corresponding setting of thepostage meter setting lever 23 arranged according to a decimal system ofnumeration.

Each solenoid consists of means for shifting the position of a shiftableelement 24, 25, 26 or 27, advantageously in the form of a permutationsector rotatable around an axis 28, from a rest position against a stop29 to a second position'slightly displaced therefrom. The energizedsolenoids operate against a return spring 30 and respectively maintaintheir permutation elements in the second position apart from the stop 29so long as they are energized. Axle 28 and stop 29 are rod-like in formand extend between a pair of side plates or frames 31, only one of whichis shown in FIG. II. A stationary stop or index plate 32 is supportedfrom frame 31 by axle 28 and stop 29 so that it has an edge 33 inalignment with the edges 34 of the permutation sectors and adjacentthereto. No-tches 35 are provided in the edges 34 of the permutationsectors 24, 25, 26, and 27 and in the edge 33 of stop plate 32 in such acombination of positions on the sectors that only one position along thesectors between the limits of the group of notches exist at which fivenotches are in line for each permutation of the sectors as determined bythe solenoids.

Each factor of the postage meter is set by a lever 23 which is driven toa position corresponding to that digit represented by the group of fivealigned notches 35 in the permutation sectors and the stationary stopplate by means of a setting link 36 coupled thereto by a pin 37 ridingin a T-slot 38 best seen in FIG. III. This slot is provided to introducesome flexibility in the linkage so that strong detenting forces inherentin the postage meter setting lever mechanism (not shown) are permittedto function despite slight misorientation between the lever 23 and thesetting link 36. The setting link in turn is driven by a bifurcatedlever 39 which is pivoted on axle 28 for rotation coaxially of the arcof the permutation sectors 24 through 27.

An indexing means is provided in the form'of a stopping pawl 40 havingan inclined plane 41 along its effective edge 41a (as best seen in FIG.V) which is arranged to engage the edges 33 and 34 of the permutationsectors and the stationary plate. Pawl 40 is urged against the edges ofthe permutation sectors by spring 42 embracing the shaft 43 journaledbetween the arms of lever 39 and supporting pawl 40 for rotation. Adrive cam 44 is secured to a cam shaft 45. Cam 44 and shaft 45 arerotated by means to be described below. Cam 44 urges drive lever 39 to aposition beyond the limits of the group of slots on the permutationsectors and stationary plate through cam follower 46 in the form of aroller mounted on the drive lever by a shaft 47. Rotation of the drivecam thus positioned the drive lever so that the pawl 40 engages edges 33and 34 at a position beyond the zero position for the postage metersetting lever. This drive operates against-a tension spring 48. Thus, asthe drive cam retreats, spring 48 con-tracts to carry the lever 39 andstopping pawl 40 toward the ninth position or opposite limit on thepermutation sectors.

In practice the solenoid drivers have two operating states available asdetermined from the counter, the first, with the triode in its output(not shown) heavily conducting or, the second with it cutoff. Thus, thesolenoids 15 through 18 individual to each triode are either deenergizedor energized. When the solenoids are energized, the sectors to whichthey are coupled are drawn to the right as viewed in FIG. II and to theleft as viewed in FIG. III. When no solenoid force is. imposed upon thesectors the spring fingers 30 individual to those sectors urge them tothe left as viewed in FIG. H and to the right as viewed in FIG. III sotheir ends abut the stop 29. Only a light spring force is imposed by thefingers 30 while the force of the solenoids is much greater, that forceresulting in a net force after the spring force has been overcome whichis suflicient to maintain the sectors displaced to their energizedposition despite the drag imposed by the travel of the pawl 40 overtheir edges 33 and 34 during the searching interval of the cycle whileit travels toward the stop 29 and tends to urge the sectors toward thatstop. As is evident from the description below of the operation of thecams carried by shaft 45, during all but the initial and final portionsof the cycle of shaft 45 the solenoids 15 through 18 have their circuitsenabled so that if the coded signal dictates, they are energized throughat least the entire search portion of the cycle to maintain the codingposition of the sectors 24 through 27. The four stage binary code canthus be converted to the decimal system by energizing solenoids in thefollowing pattern:

None

solenoid 15 solenoid 16 solenoids 15 and 16 solenoids 16 and 17solenoids 15, 16 and 17 solenoids 17 and 18 solenoids 15, 17 and 18solenoids 16, 17 and 18 solenoids 15, 16, 17 and 18 As shown in FIG. IIsolenoids 15, 16 and 17 are energized to draw permutation sectors 24, 25and 26 to the right by means of rods 49, '50 and 51 respectively,connected to their armatures 19, 20 and 21. It will be noted thatnotches 35 in the edges of all sectors and the stop plate are aligned atposition No. 5. Thus, with sector 27 urged against stop 29 by spring 30and sectors 24, 25 and 26 shifted by their solenoids, the drive lever,when no longer driven to the right by cam 44, returns to the left underthe impetus of spring 48 until pawl edge 41a is in registry withposition No. 5. The pawl rides along a smooth, continuous are made up ofthe several aligned sector arcs until it reaches position No. 5. As thepawl reaches that position, it is forced into the aligned notches byspring 42 locking the drive lever, the postage meter setting lever 23,and the permutation sectors 24 through 27 in positions corresponding tonotch 53, the No. 5 notch on stationary stop plate 32.

As will be explained below, the repositioning of the sectors 24 through27 in accordance with the count fed the decoder is urged by thesolenoids during the first portion of the rotation of shaft 45. Suchrepositioning is prevented until the drive cam 44 picks up lever 39thereby lifting pawl 40 out of the slot in which it was positionedduring the preceding operating cycle by the action of incline plane 41on its leading edge. It should be noted that the pressure imposed by thesprings is insufficient to shift those sectors 24 through 27 which aredisplaced from the stop 29 inasmuch as that pressure when translated toa pawl lifting pressure by the urging of the trailing edge b (as bestseen in FIG. V) of notch 35 on a sector against the inclined face 41 isinsufficient to overcome the pressure of spring 42 urging pawl 46 intothe notches. Further, the solenoids if energized while the pawl isseated within a group of aligned notches 35 are ineffective to shift thesectors since such energization urges the leading edges 35a of thenotches 35 against the latching face of the pawl 40. Since notch leadingedge 35a is parallel with the latching face of pawl til a force tendingto move an edge 35a against the pawl generates no component of forcetending to lift the pawl. Pawl 40 can be lifted free of the notches 35only by driving the lever 39 in a clockwise direction as viewed in FIGS.II and V. This is accomplished by the motor driven cam 44 acting on thefollower 46 mounted on the lever 39. That cam will drive the lever in aclockwise direction thereby moving the pawl 46 with respect to thenotches 35 to carry the inclined face 41 of the pawl into engagementwith the trailing edges 35!; of the notches. The force generated by themotor is sufficient to generate a component at the inclined face 41lifting the pawl 46 against the force imposed by spring 42 so that thepawl is released from the notch 35. Until the pawl is released, itsengagement with notch 35 in stationary stop plate 32 positively fixesthe position of the sectors despite any changes in the forces exerted bythe solenoids 15 through 18. The pawl 40' is lifted completely free ofthe edges 34 of the movable sectors 24 through 27 at the limit of itsmotion, at the zero end of the sectors, by a raised portion 52 on theedge 33 of stationary stop plate 32, thereby, removing any forcesretarding the sector resetting operation which might be imposed by thefrictional engagement of the edge 41a of the pawl with the edges 34 ofthe sectors. Accordingly, at the time the searching operation of thepawl is initiated the sectors have been reset and they are maintainedreset by the energization of appropriate solenoids during the search.

The decoder of FIGS. III and IV consists of three electro-mechanicaldecoder sections 54, 55 and 56 of the type shown in FIG. II. Thesedecoders translate the dollars and cents information from the computerinto corresponding settings for the dollars and cents levers of thepostage meter. The selector structure also includes a drive motor 57, asingle revolution clutch 58, an index drive velocity control mechanismor retarder 59', and a group of cam operated control contacts for thevarious circuits associated with the operation of the selector.

Drive motor 57 runs continuously and is coupled to the single revolutionclutch 58 by means of a gear train 60 offering a gear reduction to 60rpm. in the preferred embodiment. Clutch 58 couples the drive motor 57to the cam shaft common to all decoder sections through the gear trainincluding gear 62. Operation of the computer control circuit,advantageously after the scale has ceased to oscillate as indicated bythe motion detecting circuit, and the readout mechanism has beenconditioned to scan a complete readout cycle and feed that informationto the computer, energizes a clutch solenoid 61 to engage the clutch forone revolution of the cam shaft 45.

In addition to the three identical drive cams 44 for respective levers39 of the individual decoders 54, and 56 the cam shaft also has a pairof circuit actuating cams 63 and 64, which actuates electrical contacts,and a retarding cam 65 whose function is to retard the velocity of thelevers 39 as the pawl seeks an aligned series of slots on their return.During the first half revolution of the cam shaft the three drive cams,all set in identical angular positions on the shaft, are arranged todrive the decoder levers 39 toward the zero end of the permutationsectors as shown in FIG. III. During the second half revolution eachlever is driven back toward the nine end of the permutation sectors asthe drive cams recede. It is during this half of the cycle that the pawl40, attached to each selector lever 39, seeks and latches in theposition of the five-in-line notches on the edges of the permutationsectors. The power causing the levers to recede as supplied by spring 48is also the means for setting the postage meter levers through thecoupling of the links 36.

The speed with which the setting levers 39 recede during the second halfof the cam shaft revolution should be controlled so that the velocity ofthe pawl 40" over the edges 33 and 34 of the permutation sectors assuresthat it will enter an aligned series of notches and lock in thatposition. One means of controlling the velocity of the searching pawl orindexing means during this portion of the cycle is to utilize a drivingmotor 57 which opposes any tendency to increase its speed due to theaiding force of the springs 43 applied to the cam shaft 45 through therollers 46 engaging cams 44. An electric motor having dynamic brakingcharacteristics will provide such a result when coupled to the cam shaftas by a suitable gear train or cams. In the embodiment illustrated, analternative form of retarding mechanism is employed. This mechanism isan oil dashpot 66 coupled to the cam shaft to restrict its speed ofrotation during the second half of its operating cycle. This coupling iseffected through the medium of an essentially circular cam coupled tothe cam shaft 45 so that its minimum diameter becomes effective onfollower 67 at the position shown in FIG. III at the instant that thesetting levers 39 have been driven to their maximum excursion at thezero end of the permutation sectors. The inward motion of follower 67present little loading on cam 65' and shaft 45 since the dashpot isvalved to permit the withdrawal of rod therefrom. This withdrawal isaided by tension spring which draws arm 88 upward and thereby maintainsfollower 67 against cam 65. Further motion of the cam shaft causes theeffective cam face for drive cams 44 to recede so that tension spring 48tends to accelerate the speed of rotation of the cam shaft. However, cam65 picks up a load through the linkage provided by cam follower 67rotatably mounted on connecting arm 68. Arm 68 is pivoted around shaft69 and pivotally connected to the piston rod 76 of dashpot 66. Thus, theoutward motion of follower 67 from shaft 45 is opposed by the action ofthe dashpot, thereby retarding the speed of rotation of that shaft. Thedegree of retardation can conveniently be adjusted by adjusting thevalve of the dashpot whereby the speed of rotation during the secondhalf revolution of the cam shaft is controlled.

The two remaining earns 63 and 64 on shaft 45 drive electrical contactsthrough the medium of followers 71 and 72, respectively. Cam 63 andfollower 71 are arranged to disengage permitting the closure of contacts73 throughout most of the revolution of the cam shaft and to engage toopen the contacts at the cam shaft stop position. In practice, as isexplained more fully in the above noted Bell and Williams application,several normally open sets of contacts can be actuated by cam 63depending on the functions required. However, in the interest of clarityonly one set of contacts is illustrated here. Contacts actuated in thismanner may function to lockout the transmission of further informationfrom the readout mechanism of the scale to the multiplier and computersections in order to prevent the values in the drivers to the solenoids15 through 13 from being altered, to complete energization circuits forthe solenoids 15 through 18, to recycle portions of the computer such asthat wherein the computing factor is selected, and to activate guardcircuits preventing malfunctioning during the decoding operation.Contacts 73 are opened at the end of the shaft rotation to release thosecircuits performing the above functions thereby conditioning the systemfor its next utilization.

Cam '64 is arranged to engage follower 72 and to close electricalcontacts 74 near the end of the cam shaft revolution and to releasethose contacts as the cam shaft reaches its stopped position. Theclosure of contacts 74 energizes a print solenoid (not shown) whichoperates the postage meter print lever (not shown) to print a meteredlabel of the value corresponding to that estab lished by the decoder.

The organization of the cam shaft 45 and the cams thereon is shown indetail in FIG. IV. As illustrated in FIG. HI the shaft is journaled inthe side portions of the housing 76 and 77 corresponding to the sideplates 31 of FIG. II. The drive mechanism including gear 62, the cams 44operating drive levers 3-9, and the contact actuating cams 63 and 64 areall within the housing and bounded by side plates 76 and 77 while cam 65coupled to the retarding mechanism is outside of plate 76. The stoppedposition or starting position for the shaft is such that the contactfollower 71 is engaged by the high surface 78 of cam 63. In thisposition the cams 44 have retreated to the maximum extent toward shaft45, i.e. their effective surface engaging drive lever followers 46 isclosest to the shaft, so that at the end of the preceding cycle thelevers were free to carry pawl '40 to the No. 9 position in its search.Since the followers 4 6 are displaced essentially 180 around shaft 45from follower 71, the minimum extensions of cams 44 are displaced inthis manner with respect to face 78 of cam 63. Drive gears 62 rotatesshaft 45 clockwise. Since the retarding mechanism is designed to becomeeffective during the retreat of the faces of cams 44 toward shaft 45, itis arranged to have its minimum effective departure from the shaftcoincide with the maximum effective departure of the faces of cams 44.Cam 65 is effective at a point displaced about 90 clockwise around shaft45 from that for earns 44. Accordingly, the maximum diameter on cam 65is shown displaced in the same manner with respect to the minimumdiameters on cams 44, about 90 clockwise from those minimum diameters.Contact actuating cam 64 is intended to actuate the print mechanismafter the decoding operation is completed and therefore it is arrangedto pick up follower 72 near the end of the cycle and release itessentially at the end. Follower 72 is displaced counter clockwise withrespect to follower '71. Cam 64 is arranged so that its trailing edge 79disengages follower 72 just prior to the disengagement of the trailingportion of face 78 from follower 71 and therefore is displaced counterclockwise slightly from face 78.

While the invention has been described as applied to a decoding devicefor a specific application it is to be understood that the features ofthis mechanism might as readily be applied to other forms of permutationdevices. In particular, it is contemplated as within the scope of thisinvention to utilize a stationary, positioning, and latching mechanismto accurately maintain the position of a movable element during criticalstages of the operation of a permutation device as during the printcycle of the postal meter in the example, and to employ the speedcontrol mechanisms which have been utilized in this invention wheremechanical movements of the type disclosed are employed. Accordingly, itis to be understood that the described embodiment is presented asillustrative of the invention and is not to be interpreted in a limitingsense.

What is claimed is:

l. A mechanical translating mechanism comprising an axis, a plurality ofelements rotatable about said axis, an arcuate sector on each elementhaving a periphery defined by a given radius from said axis and having aplurality of notches therein, a fixed element having an arcuate sectorwith a periphery defined by a radius from said axis equal to said givenradius and in alignment with said rotatable elements, said periphery ofsaid arcuate sector of said fixed element having a plurality of notchestherein, means for selectively rotating said rotatable elements to aligna group of notches on said fixed and rotatable elements, a leverrotatable about said axis, a drive link coupled to said lever on oneside of said axis, an indexing latch on said lever on said one side ofsaid axis and adjacent said drive link, means urging said latch againstthe peripheries of said arcuate sectors on said elements, first meansurging said lever to a first position wherein said latch is on one sideof said plurality of notches on said sectors, and driving meansoperatively connected to said lever to overpower said first means and toposition said lever whereby said latch is on a second side opposite saidone side of said plurality of notches in said sectors, said drivingmeans releasing said lever and terminating the overpowering of saidfirst means upon positioning said latch on said second side whereby saidfirst means tends to move said lever toward said first position toposition said latch in registry with said aligned group of notches andto position said drive link along an are about said axis.

2. A mechanical translating mechanism comprising an axis, a plurality ofelements rotatable about said axis, an arcuate sector on each elementhaving a periphery defined by a given radius from said axis and having aplurality of notches therein, a fixed element having an arcuate sectorwith a periphery defined by a radius from said axis equal to said givenradius and in alignment with said rotatable elements, said periphery ofsaid arcuate sector of said fixed element having a plurality of notchestherein, means for selectively rotating said rotatable elements to aligna group of notches on said fixed and r0- tatable elements, a leverrotatable about said axis, a drive link coupled to said lever on oneside of said axis, an indexing latch on said lever on said one side ofsaid axis and adjacent said drive link, means urging said latch againstthe peripheries of said arcuate sectors on said elements, first meansurging said lever to a first position wherein said latch is on one sideof said plurality of notches on said sectors, driving means operativelyconnected to said lever to overpower said first means and to positionsaid lever whereby said latch is on a second side opposite said one sideof said plurality of notches in said sectors, said driving meansreleasing said lever and termihating the overpowering of said firstmeans upon positioning said latch on said second side whereby said firstmeans tends to move said lever toward said first position to positionsaid latch in registry with said aligned group of notches and toposition said drive link along an are about said axis, and meansretarding the speed of movement of said lever toward said firstposition. I

3. A mechanism as set forth in claim 2 wherein said retarding means is adashpot.

4. A mechanical translating mechanism comprising an axis, a plurality ofelements rotatable about said axis, an arcuate sector on each elementhaving a periphery defined by a given radius from said axis and having aplurality of notches therein, a fixed element having an arcuate sectorwith a periphery defined by a radius from said axis equal to said givenradius and in alignment with said rotatable elements, said periphery ofsaid arcuate sector of said fixed element having a plurality of notchestherein, means for selectively rotating said rotatable elements to aligna group of notches on said fixed and rotatable elements, a leverrotatable about said axis, a drive link coupled to said lever on oneside of said axis, an indexing latch on said lever on said one side ofsaid axis and adjacent said drive link, means urging said latch againstthe perlpheries of said arcuate sectors on said elements,

first means urging said lever to a first position wherein said latch ison one side of said plurality of notches on said sectors, driving meansoperatively connected to said lever to overpower said first means and toposition said lever whereby said latch is on a second side opposite saidone side of said plurality of notches in said sectors, said drivingmeans releasing said lever and terminating the 10 overpowering of saidfirst means upon positioning of References Cited in the file of thispatent said latch on said second side whereby said first means UNITEDSTATES PATENTS tends to move said lever toward said first position to 7position said latch in registry with said aligned group ffggi :93:52 eta1 XL' Z of notches and to position said drive link around an are 51726539 Carroll Sept 1929 about said axis, means to free said latchmeans from 1:843:986 Peirce 1 2 said ancuate sectors of all rotatableelements while said 1,950,187 Mansel Man 6 4 latch is on said secondside of said plurality of notches 2 503 03 Gollwitzer May 213 1950 onsaid sectors, and means retarding the speed of move- 10 2 675,176 P iApr 13, 1954 ment of said lever toward said first position. 2,7 57,866Johnson Aug. 7, 1956

